Pier blocks with ABU-44 bracket inserted

Started by Drew, December 13, 2007, 02:27:16 PM

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Drew

Hi folks,

I read the thread at http://countryplans.com/smf/index.php?topic=2662.0 and got really close, but I'd appreciate some confirmation.

I'm working from the Small House Plans for the post and beam foundation.  I can't get the pier block with the pre-installed bracket.  The building supply store guy says I can insert a Simpson ABU-44 into a pier block that has a ~5/8" hole in the top of it (And add epoxy, most likely, thought the guy didn't know).

Is this strong enough for the spec?  It would make things easier.

My alternative would be to use EPB-44HDG elevated post bases pressed into concrete in an 8" concrete block.  I'm less interested in mixing concrete for 21 piers than sticking a bunch of bases into blocks, but I will if that's the best solution.

Either solution will rest on my 12"x12" paver footing.

Thanks again.

Drew

MountainDon

A home made thing like this should be more or less equivalent to the manufactured blocks idea. You'd have to epoxy the unit to the block to provide uplift resistance. If the block and bracket are notsecured to what's below this may be a moot point.

Do you have local approvals to be concerned about? Building codes? Before getting involved as to what you should do you should check with them, if you are building to code.

You can cut down on the number of blocks/piers and the amount of digging and concreting my increasing the size of the support beams as another idea to consider. That is IF your ground is able to support the higher loading that will happen with a reduction in the number of piers.

What size cabin are you building?

Just because something has been done and has not failed, doesn't mean it is good design.


John Raabe

Here is a diagram of the pier block setup and you could make your own out of any of several types of concrete blocks. The metal bracket helps support against uplift and sideward forces but for 99.999% of its life just transfers compression forces downward into the underlying soil. Any bracket that holds the beam up above the concrete and can be nailed into the beam will work.

None of us are as smart as all of us.

Drew

Hi John,

Thanks for this.

I'm working from the foundation plan that came with the Small House Plans.  I'm using a 16"x16"x2" paver on undisturbed soil, and plan to put the pier block on top of that.  Did I misunderstand the plan?  Should I pour these piers?

We reach undisturbed earth  few inches down, pretty much under the sod. We're in the California Central Valley at 400' elevation.  It doesn't snow and very rarely goes below freezing for a night.  Our rainiest month is January with 5.5 inches (Yeah, I know you Washington guys drink our annual rainfall before breakfast.   ;) ).  The soil is more clay than sand with lots of small rocks in it.  The building is 18'x24'.  I've planned for three beams, each with 7 posts on 4' centers.  The site has a gentle slope so there should be no pooling anywhere near the house.

I hope I've planned the foundation properly for the climate and conditions.  However, I'd rather hear I'm wrong now than in a year or three.

If the foundation is okay, do I need to attach the pier to the paver?  I saw someone on this site had poured concrete over the piers and pavers.  Would that be sufficient?

Thanks,
Drew

John Raabe

If the soil has clay you should be sure it will drain well and, more importantly, not expand when it freezes. Test this in your freezer. Otherwise you would be wise to dig out the native soils and put in crushed rock down to frost depth.

Your layout should be fine and with three beams and 4' o/c for the piers means you will not be overloading your pavers. If the soil is solid and undisturbed you should be fine bearing right on the paver. Notice in my diagram that the 12x12 pier block carries the load (at a 45ยบ angle) down through the gravel to the 16x16 bearing soil below. If you can get 12x12 concrete blocks and pour the center with your bracket that would spread the weight out over the paver. You don't want too much of a point load in the center of a thin paver, especially in softer soil.
None of us are as smart as all of us.